Merge branch 'spi/next' of git://git.secretlab.ca/git/linux-2.6

* 'spi/next' of git://git.secretlab.ca/git/linux-2.6:
spi/amba-pl022: work in polling or interrupt mode if pl022_dma_probe fails
spi/spi_s3c24xx: Use spi_bitbang_stop instead of spi_unregister_master in s3c24xx_spi_remove
spi/spi_nuc900: Use spi_bitbang_stop instead of spi_unregister_master in nuc900_spi_remove
spi/spi_tegra: use spi_unregister_master() instead of spi_master_put()
spi/spi_sh: use spi_unregister_master instead of spi_master_put in remove path
spi: Use void pointers for data in simple SPI I/O operations
spi/pl022: use cpu_relax in the busy loop
spi/pl022: mark driver non-experimental
spi/pl022: timeout on polled transfer v2
spi/dw_spi: improve the interrupt mode with the batch ops
spi/dw_spi: change poll mode transfer from byte ops to batch ops
spi/dw_spi: remove the un-necessary flush()
spi/dw_spi: unify the low level read/write routines

drivers/spi/Kconfig

···
 	  This enables using the SPI master controller on the Orion chips.
 
 config SPI_PL022
-	tristate "ARM AMBA PL022 SSP controller (EXPERIMENTAL)"
-	depends on ARM_AMBA && EXPERIMENTAL
+	tristate "ARM AMBA PL022 SSP controller"
+	depends on ARM_AMBA
 	default y if MACH_U300
 	default y if ARCH_REALVIEW
 	default y if INTEGRATOR_IMPD1

drivers/spi/amba-pl022.c

···
  * GNU General Public License for more details.
  */
 
-/*
- * TODO:
- * - add timeout on polled transfers
- */
-
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/device.h>
···
 #define ENABLE_ALL_INTERRUPTS (~DEFAULT_SSP_REG_IMSC)
 
 #define CLEAR_ALL_INTERRUPTS  0x3
+
+#define SPI_POLLING_TIMEOUT 1000
 
 
 /*
···
 					    pl022->master_info->dma_filter,
 					    pl022->master_info->dma_rx_param);
 	if (!pl022->dma_rx_channel) {
-		dev_err(&pl022->adev->dev, "no RX DMA channel!\n");
+		dev_dbg(&pl022->adev->dev, "no RX DMA channel!\n");
 		goto err_no_rxchan;
 	}
 
···
 					    pl022->master_info->dma_filter,
 					    pl022->master_info->dma_tx_param);
 	if (!pl022->dma_tx_channel) {
-		dev_err(&pl022->adev->dev, "no TX DMA channel!\n");
+		dev_dbg(&pl022->adev->dev, "no TX DMA channel!\n");
 		goto err_no_txchan;
 	}
 
 	pl022->dummypage = kmalloc(PAGE_SIZE, GFP_KERNEL);
 	if (!pl022->dummypage) {
-		dev_err(&pl022->adev->dev, "no DMA dummypage!\n");
+		dev_dbg(&pl022->adev->dev, "no DMA dummypage!\n");
 		goto err_no_dummypage;
 	}
 
···
 	dma_release_channel(pl022->dma_rx_channel);
 	pl022->dma_rx_channel = NULL;
 err_no_rxchan:
+	dev_err(&pl022->adev->dev,
+			"Failed to work in dma mode, work without dma!\n");
 	return -ENODEV;
 }
 
···
 	struct spi_transfer *transfer = NULL;
 	struct spi_transfer *previous = NULL;
 	struct chip_data *chip;
+	unsigned long time, timeout;
 
 	chip = pl022->cur_chip;
 	message = pl022->cur_msg;
···
 		       SSP_CR1(pl022->virtbase));
 
 		dev_dbg(&pl022->adev->dev, "polling transfer ongoing ...\n");
-		/* FIXME: insert a timeout so we don't hang here indefinitely */
-		while (pl022->tx < pl022->tx_end || pl022->rx < pl022->rx_end)
+
+		timeout = jiffies + msecs_to_jiffies(SPI_POLLING_TIMEOUT);
+		while (pl022->tx < pl022->tx_end || pl022->rx < pl022->rx_end) {
+			time = jiffies;
 			readwriter(pl022);
+			if (time_after(time, timeout)) {
+				dev_warn(&pl022->adev->dev,
+				"%s: timeout!\n", __func__);
+				message->state = STATE_ERROR;
+				goto out;
+			}
+			cpu_relax();
+		}
 
 		/* Update total byte transferred */
 		message->actual_length += pl022->cur_transfer->len;
···
 		/* Move to next transfer */
 		message->state = next_transfer(pl022);
 	}
-
+out:
 	/* Handle end of message */
 	if (message->state == STATE_DONE)
 		message->status = 0;
···
 	if (platform_info->enable_dma) {
 		status = pl022_dma_probe(pl022);
 		if (status != 0)
-			goto err_no_dma;
+			platform_info->enable_dma = 0;
 	}
 
 	/* Initialize and start queue */
···
  err_init_queue:
 	destroy_queue(pl022);
 	pl022_dma_remove(pl022);
- err_no_dma:
 	free_irq(adev->irq[0], pl022);
  err_no_irq:
 	clk_put(pl022->clk);

drivers/spi/dw_spi.c

···
 	u8 bits_per_word;
 	u16 clk_div;		/* baud rate divider */
 	u32 speed_hz;		/* baud rate */
-	int (*write)(struct dw_spi *dws);
-	int (*read)(struct dw_spi *dws);
 	void (*cs_control)(u32 command);
 };
 
···
 }
 #endif /* CONFIG_DEBUG_FS */
 
-static void wait_till_not_busy(struct dw_spi *dws)
+/* Return the max entries we can fill into tx fifo */
+static inline u32 tx_max(struct dw_spi *dws)
 {
-	unsigned long end = jiffies + 1 + usecs_to_jiffies(5000);
+	u32 tx_left, tx_room, rxtx_gap;
 
-	while (time_before(jiffies, end)) {
-		if (!(dw_readw(dws, sr) & SR_BUSY))
-			return;
-		cpu_relax();
+	tx_left = (dws->tx_end - dws->tx) / dws->n_bytes;
+	tx_room = dws->fifo_len - dw_readw(dws, txflr);
+
+	/*
+	 * Another concern is about the tx/rx mismatch, we
+	 * though to use (dws->fifo_len - rxflr - txflr) as
+	 * one maximum value for tx, but it doesn't cover the
+	 * data which is out of tx/rx fifo and inside the
+	 * shift registers. So a control from sw point of
+	 * view is taken.
+	 */
+	rxtx_gap =  ((dws->rx_end - dws->rx) - (dws->tx_end - dws->tx))
+			/ dws->n_bytes;
+
+	return min3(tx_left, tx_room, (u32) (dws->fifo_len - rxtx_gap));
+}
+
+/* Return the max entries we should read out of rx fifo */
+static inline u32 rx_max(struct dw_spi *dws)
+{
+	u32 rx_left = (dws->rx_end - dws->rx) / dws->n_bytes;
+
+	return min(rx_left, (u32)dw_readw(dws, rxflr));
+}
+
+static void dw_writer(struct dw_spi *dws)
+{
+	u32 max = tx_max(dws);
+	u16 txw = 0;
+
+	while (max--) {
+		/* Set the tx word if the transfer's original "tx" is not null */
+		if (dws->tx_end - dws->len) {
+			if (dws->n_bytes == 1)
+				txw = *(u8 *)(dws->tx);
+			else
+				txw = *(u16 *)(dws->tx);
+		}
+		dw_writew(dws, dr, txw);
+		dws->tx += dws->n_bytes;
 	}
-	dev_err(&dws->master->dev,
-		"DW SPI: Status keeps busy for 5000us after a read/write!\n");
 }
 
-static void flush(struct dw_spi *dws)
+static void dw_reader(struct dw_spi *dws)
 {
-	while (dw_readw(dws, sr) & SR_RF_NOT_EMPT) {
-		dw_readw(dws, dr);
-		cpu_relax();
+	u32 max = rx_max(dws);
+	u16 rxw;
+
+	while (max--) {
+		rxw = dw_readw(dws, dr);
+		/* Care rx only if the transfer's original "rx" is not null */
+		if (dws->rx_end - dws->len) {
+			if (dws->n_bytes == 1)
+				*(u8 *)(dws->rx) = rxw;
+			else
+				*(u16 *)(dws->rx) = rxw;
+		}
+		dws->rx += dws->n_bytes;
 	}
-
-	wait_till_not_busy(dws);
-}
-
-static int null_writer(struct dw_spi *dws)
-{
-	u8 n_bytes = dws->n_bytes;
-
-	if (!(dw_readw(dws, sr) & SR_TF_NOT_FULL)
-		|| (dws->tx == dws->tx_end))
-		return 0;
-	dw_writew(dws, dr, 0);
-	dws->tx += n_bytes;
-
-	wait_till_not_busy(dws);
-	return 1;
-}
-
-static int null_reader(struct dw_spi *dws)
-{
-	u8 n_bytes = dws->n_bytes;
-
-	while ((dw_readw(dws, sr) & SR_RF_NOT_EMPT)
-		&& (dws->rx < dws->rx_end)) {
-		dw_readw(dws, dr);
-		dws->rx += n_bytes;
-	}
-	wait_till_not_busy(dws);
-	return dws->rx == dws->rx_end;
-}
-
-static int u8_writer(struct dw_spi *dws)
-{
-	if (!(dw_readw(dws, sr) & SR_TF_NOT_FULL)
-		|| (dws->tx == dws->tx_end))
-		return 0;
-
-	dw_writew(dws, dr, *(u8 *)(dws->tx));
-	++dws->tx;
-
-	wait_till_not_busy(dws);
-	return 1;
-}
-
-static int u8_reader(struct dw_spi *dws)
-{
-	while ((dw_readw(dws, sr) & SR_RF_NOT_EMPT)
-		&& (dws->rx < dws->rx_end)) {
-		*(u8 *)(dws->rx) = dw_readw(dws, dr);
-		++dws->rx;
-	}
-
-	wait_till_not_busy(dws);
-	return dws->rx == dws->rx_end;
-}
-
-static int u16_writer(struct dw_spi *dws)
-{
-	if (!(dw_readw(dws, sr) & SR_TF_NOT_FULL)
-		|| (dws->tx == dws->tx_end))
-		return 0;
-
-	dw_writew(dws, dr, *(u16 *)(dws->tx));
-	dws->tx += 2;
-
-	wait_till_not_busy(dws);
-	return 1;
-}
-
-static int u16_reader(struct dw_spi *dws)
-{
-	u16 temp;
-
-	while ((dw_readw(dws, sr) & SR_RF_NOT_EMPT)
-		&& (dws->rx < dws->rx_end)) {
-		temp = dw_readw(dws, dr);
-		*(u16 *)(dws->rx) = temp;
-		dws->rx += 2;
-	}
-
-	wait_till_not_busy(dws);
-	return dws->rx == dws->rx_end;
 }
 
 static void *next_transfer(struct dw_spi *dws)
···
 
 static void int_error_stop(struct dw_spi *dws, const char *msg)
 {
-	/* Stop and reset hw */
-	flush(dws);
+	/* Stop the hw */
 	spi_enable_chip(dws, 0);
 
 	dev_err(&dws->master->dev, "%s\n", msg);
···
 
 static irqreturn_t interrupt_transfer(struct dw_spi *dws)
 {
-	u16 irq_status, irq_mask = 0x3f;
-	u32 int_level = dws->fifo_len / 2;
-	u32 left;
+	u16 irq_status = dw_readw(dws, isr);
 
-	irq_status = dw_readw(dws, isr) & irq_mask;
 	/* Error handling */
 	if (irq_status & (SPI_INT_TXOI | SPI_INT_RXOI | SPI_INT_RXUI)) {
 		dw_readw(dws, txoicr);
 		dw_readw(dws, rxoicr);
 		dw_readw(dws, rxuicr);
-		int_error_stop(dws, "interrupt_transfer: fifo overrun");
+		int_error_stop(dws, "interrupt_transfer: fifo overrun/underrun");
 		return IRQ_HANDLED;
 	}
 
+	dw_reader(dws);
+	if (dws->rx_end == dws->rx) {
+		spi_mask_intr(dws, SPI_INT_TXEI);
+		dw_spi_xfer_done(dws);
+		return IRQ_HANDLED;
+	}
 	if (irq_status & SPI_INT_TXEI) {
 		spi_mask_intr(dws, SPI_INT_TXEI);
-
-		left = (dws->tx_end - dws->tx) / dws->n_bytes;
-		left = (left > int_level) ? int_level : left;
-
-		while (left--)
-			dws->write(dws);
-		dws->read(dws);
-
-		/* Re-enable the IRQ if there is still data left to tx */
-		if (dws->tx_end > dws->tx)
-			spi_umask_intr(dws, SPI_INT_TXEI);
-		else
-			dw_spi_xfer_done(dws);
+		dw_writer(dws);
+		/* Enable TX irq always, it will be disabled when RX finished */
+		spi_umask_intr(dws, SPI_INT_TXEI);
 	}
 
 	return IRQ_HANDLED;
···
 static irqreturn_t dw_spi_irq(int irq, void *dev_id)
 {
 	struct dw_spi *dws = dev_id;
-	u16 irq_status, irq_mask = 0x3f;
+	u16 irq_status = dw_readw(dws, isr) & 0x3f;
 
-	irq_status = dw_readw(dws, isr) & irq_mask;
 	if (!irq_status)
 		return IRQ_NONE;
 
 	if (!dws->cur_msg) {
 		spi_mask_intr(dws, SPI_INT_TXEI);
-		/* Never fail */
 		return IRQ_HANDLED;
 	}
 
···
 /* Must be called inside pump_transfers() */
 static void poll_transfer(struct dw_spi *dws)
 {
-	while (dws->write(dws))
-		dws->read(dws);
-	/*
-	 * There is a possibility that the last word of a transaction
-	 * will be lost if data is not ready. Re-read to solve this issue.
-	 */
-	dws->read(dws);
+	do {
+		dw_writer(dws);
+		dw_reader(dws);
+		cpu_relax();
+	} while (dws->rx_end > dws->rx);
 
 	dw_spi_xfer_done(dws);
 }
···
 	dws->tx_end = dws->tx + transfer->len;
 	dws->rx = transfer->rx_buf;
 	dws->rx_end = dws->rx + transfer->len;
-	dws->write = dws->tx ? chip->write : null_writer;
-	dws->read = dws->rx ? chip->read : null_reader;
 	dws->cs_change = transfer->cs_change;
 	dws->len = dws->cur_transfer->len;
 	if (chip != dws->prev_chip)
···
 
 		switch (bits) {
 		case 8:
-			dws->n_bytes = 1;
-			dws->dma_width = 1;
-			dws->read = (dws->read != null_reader) ?
-					u8_reader : null_reader;
-			dws->write = (dws->write != null_writer) ?
-					u8_writer : null_writer;
-			break;
 		case 16:
-			dws->n_bytes = 2;
-			dws->dma_width = 2;
-			dws->read = (dws->read != null_reader) ?
-					u16_reader : null_reader;
-			dws->write = (dws->write != null_writer) ?
-					u16_writer : null_writer;
+			dws->n_bytes = dws->dma_width = bits >> 3;
 			break;
 		default:
 			printk(KERN_ERR "MRST SPI0: unsupported bits:"
···
 		txint_level = dws->fifo_len / 2;
 		txint_level = (templen > txint_level) ? txint_level : templen;
 
-		imask |= SPI_INT_TXEI;
+		imask |= SPI_INT_TXEI | SPI_INT_TXOI | SPI_INT_RXUI | SPI_INT_RXOI;
 		dws->transfer_handler = interrupt_transfer;
 	}
 
···
 	if (spi->bits_per_word <= 8) {
 		chip->n_bytes = 1;
 		chip->dma_width = 1;
-		chip->read = u8_reader;
-		chip->write = u8_writer;
 	} else if (spi->bits_per_word <= 16) {
 		chip->n_bytes = 2;
 		chip->dma_width = 2;
-		chip->read = u16_reader;
-		chip->write = u16_writer;
 	} else {
 		/* Never take >16b case for MRST SPIC */
 		dev_err(&spi->dev, "invalid wordsize\n");
···
 	spi_enable_chip(dws, 0);
 	spi_mask_intr(dws, 0xff);
 	spi_enable_chip(dws, 1);
-	flush(dws);
 
 	/*
 	 * Try to detect the FIFO depth if not set by interface driver,

drivers/spi/dw_spi.h

···
 	u8			max_bits_per_word;	/* maxim is 16b */
 	u32			dma_width;
 	int			cs_change;
-	int			(*write)(struct dw_spi *dws);
-	int			(*read)(struct dw_spi *dws);
 	irqreturn_t		(*transfer_handler)(struct dw_spi *dws);
 	void			(*cs_control)(u32 command);
 

drivers/spi/spi.c

···
  * spi_{async,sync}() calls with dma-safe buffers.
  */
 int spi_write_then_read(struct spi_device *spi,
-		const u8 *txbuf, unsigned n_tx,
-		u8 *rxbuf, unsigned n_rx)
+		const void *txbuf, unsigned n_tx,
+		void *rxbuf, unsigned n_rx)
 {
 	static DEFINE_MUTEX(lock);
 

drivers/spi/spi_nuc900.c

···
 
 	platform_set_drvdata(dev, NULL);
 
-	spi_unregister_master(hw->master);
+	spi_bitbang_stop(&hw->bitbang);
 
 	clk_disable(hw->clk);
 	clk_put(hw->clk);

drivers/spi/spi_s3c24xx.c

···
 
 	platform_set_drvdata(dev, NULL);
 
-	spi_unregister_master(hw->master);
+	spi_bitbang_stop(&hw->bitbang);
 
 	clk_disable(hw->clk);
 	clk_put(hw->clk);

drivers/spi/spi_sh.c

···
 {
 	struct spi_sh_data *ss = dev_get_drvdata(&pdev->dev);
 
+	spi_unregister_master(ss->master);
 	destroy_workqueue(ss->workqueue);
 	free_irq(ss->irq, ss);
 	iounmap(ss->addr);
-	spi_master_put(ss->master);
 
 	return 0;
 }

drivers/spi/spi_tegra.c

···
 	master = dev_get_drvdata(&pdev->dev);
 	tspi = spi_master_get_devdata(master);
 
+	spi_unregister_master(master);
 	tegra_dma_free_channel(tspi->rx_dma);
 
 	dma_free_coherent(&pdev->dev, sizeof(u32) * BB_LEN,
···
 	clk_put(tspi->clk);
 	iounmap(tspi->base);
 
-	spi_master_put(master);
 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	release_mem_region(r->start, (r->end - r->start) + 1);
 

include/linux/spi/spi.h

···
  * Callable only from contexts that can sleep.
  */
 static inline int
-spi_write(struct spi_device *spi, const u8 *buf, size_t len)
+spi_write(struct spi_device *spi, const void *buf, size_t len)
 {
 	struct spi_transfer	t = {
 			.tx_buf		= buf,
···
  * Callable only from contexts that can sleep.
  */
 static inline int
-spi_read(struct spi_device *spi, u8 *buf, size_t len)
+spi_read(struct spi_device *spi, void *buf, size_t len)
 {
 	struct spi_transfer	t = {
 			.rx_buf		= buf,
···
 
 /* this copies txbuf and rxbuf data; for small transfers only! */
 extern int spi_write_then_read(struct spi_device *spi,
-		const u8 *txbuf, unsigned n_tx,
-		u8 *rxbuf, unsigned n_rx);
+		const void *txbuf, unsigned n_tx,
+		void *rxbuf, unsigned n_rx);
 
 /**
  * spi_w8r8 - SPI synchronous 8 bit write followed by 8 bit read